Within the last few years it has become desirable to provide protective coatings on frangible glass containers, particularly containers where a pressurized liquid may be contained therein. It has also become a practice in recent years to put carbonated beverages in containers of fairly large capacity such as 32 oz. and 64 oz. bottles. Glass has an inherent strength which is well known; however, it is readily recognized that much of its strength may be lost due to the surface abrasion during the service life of the container. Typically, containers are coated shortly after they are produced with lubricious coatings which provide protection during the handling of the container from the manufacturing plant to the bottling plant where they are filled with a product. These coatings are, however, of a fairly thin character and do not exhibit a cohesive strength which would be considered capable of containing glass particles or fragments if the container were to fail in use.
With this in mind, it has become advantageous to additionally protect the surface of the containers against abrasion by providing a shrink sleeve cover of polymeric material. Typically, these materials have taken the form of foam polystyrene or foamed polyethylene. These foamed materials have an impact-absorbing strength, as well as preventing scratches or abrasions of the containers' outer surface. One disadvantage, when sleeves have been placed on bottles that contain carbonated beverages, is that the sleeve is non-transparent, thus a sleeve which extends above the shoulder of the bottle into the area of the neck will effectively mask the fill level line. We have been led to believe that the visibility of the fill level was a desirable characteristic of a container. The ultimate consumer of a product contained in the bottle prefers to see that the bottle is filled to the proper level before purchasing the container. With this in mind, the present invention deals with the method and apparatus for automatically handling bottles through a shoulder and neck area encircling coating system which will apply a relatively clear, transparent layer of organic polymeric material. This coating, along with the heat shrinkable thermoplastic sleeve, will provide a container which has substantially all of its external surface provided with a covering which will prevent abrasions of the external surface of the container and have the additional advantage of preventing substantial glass fragment scattering upon breakage of the container with its pressurized contents.
U.S. Pat. No. 3,760,968 shows a sleeve-like cover which in one form provides a sleeve cover for the main body portion of the container. Another U.S. Pat. No. 3,950,199, assigned to the assignee of this application, shows a neck and shoulder coating head which essentially is the same as that utilized in the present invention; however, it being understood that the present invention is directed to the machine and process for handling the containers into and through the coating process with return of the coated containers to a conveyor, all of the foregoing operations being carried out automatically in proper timed sequence.